Background:

Promethazine hydrochloride is the first-generation antihistamine; strong antagonist of the H1 receptor and moderate mACh receptor antagonist, moderate affinity for 5-HT2A, 5-HT2C, D2 and α1-adrenergic receptors.

参考文献:
[1]. Strenkoski-Nix LC, et al. Pharmacokinetics of promethazine hydrochloride after administration of rectal suppositories and oral syrup to healthy subjects. Am J Health Syst Pharm. 2000 Aug 15;57(16):1499-505.
[2]. Fiorella D, et al. The role of the 5-HT2A and 5-HT2C receptors in the stimulus effects of hallucinogenic drugs. I: Antagonist correlation analysis. Psychopharmacology (Berl). 1995 Oct;121(3):347-56.
[3]. Seeman P, et al. Dopamine D2 receptor binding sites for agonists. A tetrahedral model. Mol Pharmacol. 1985 Nov;28(5):391-9.
[4]. Burt DR, et al. Antischizophrenic drugs: chronic treatment elevates dopamine receptor binding in brain. Science. 1977 Apr 15;196(4287):326-8.